Personal words to G-d are Divinely inspired

The words that a person converses and speaks between himself and his Maker are the aspect of ruach hakodesh (Divine inspiration), for through undertaking this, and forcing himself, and preparing himself to speak before Hashem Yisburach, Hashem Yisburach sends him words in his mouth which are the aspect of ruach hakodesh (Divine inspiration). And it is necessary to see to it, and to endeavor to innovate always, to beseech at all times with new words of appeasement and entreaties, and one merits this through purity of the heart, which one merits through the holy motion of the intellect (as is explained in the entry of Daas, article 3).

(Likutay Moharan, Torah 21 and 156. Outpouring of the Soul 64)